Manual control of electronic percussion generator with organ



y 1957 J. H. HEARNE 3,317,649

MANUAL CONTROL OF ELECTRONIC PERCUSSION GENERATOR WITH ORGAN Filed Jan/29, 1964 2 Sheets-Sheet 1 L KEV I 6W1 rel/E5 75/1/15 7 0) Harem; (if/VERA TOKS JTOP$ T AMPL/F/E)? g i Wyn/H L 40 1 1 45 K GENEKA ram 1' L j u AMPLIFIER away? 55 P/1/1L 6W/7'Ch65 50 f 4Q I NVEN TOR.

J. H. HEARN MANUAL CONTROL OF ELECTRONIC PERCUSSION GENERATOR WITH ORGAN Filed Jan. 29, 1964 MEI 2 s-Sheet 2 k d M I Ill. fi v? a VENTOR.

United States Patent 3,317,649 MANUAL CONTROL OF ELECTRONIC PERCUS- ION GENERATOR WITH ORGAN Joseph H. Hearne, Corinth, Miss., assignor to The Wurlitzer Company, Chicago, III., a corporation of Ohio Filed Jan. 29, 1964, Ser. No. 341,080 9 Claims. (Cl. 841.24)

This invention relates to an electronic musical instrument, and more particularly to an electronic organ having rhythm percussive accompanying effects.

In various places it is common practice to provide small dance bands or combinations for producing or playing popular music for dancing, or simply for entertainment. Generally speaking, a certain number of instruments is used to produce the melody. In addition, there preferably is a rhythm accompaniment, produced by one or more musicians operating with various percussive type sound generators, such as drums, blocks, brushes, cymbals, and the like. Such rhythm accompaniment is of a repetitive nature, differing in accordance with the nature of the music, i.e., fox-trot, samba, Cha-Cha, etc.

Often in a small club or public place of entertainment, the financial expense of a small orchestra is prohibitive. Thus, in order to make dancing possible, or simply for background music, a single musician may be hired to play an electronic organ, or other melody instrument. Rhythm accompaniment can be produced by an electronic rhythm device sold by the Wurlitzer Company, and known as the Sideman rhythm device. This device is disclosed and claimed in my prior application for Rhythm Device, Ser. No. 96,135 filed Mar. 16, 1961, now abandoned, and in my previous joint application for Rhythm Device, Ser. No. 103,001 filed Apr. 14, 1961, now Patent No. 3,207,835, in which the inventors are Howard E. Holman, Marvin C. Korinke and myself. Although the Sideman rhythm device produces excellent results and is extremely versatile, it does entail the use of an additional piece of equipment which in some instances may be undesirable. It also requires the organist to conform his timing to that of the rhythm device.

Accordingly, it is the primary object of the present invention to provide an electronic organ with built-in rhythm accompaniment. More specifically, it is an object of this invention to provide an electronic organ having rhythm accompaniment operated under the control of the normal playing keys and pedals of the organ.

More particularly, it is an object of this invention to provide an electronic organ having provision for bass drum and cymbal accompaniment controlled by the pedals, and a brush generator controlled by the manuals.

Other and further objects and advantages of the present invention will be apparent from the following description when taken in connection with the accompanying drawings wherein:

FIG. 1 is a perspective view of an electronic organ constructed in accordance with the principles of the present invention;

FIG. 2 is a block wiring ples of the invention;

FIG. 2A is a wiring diagram illustrating switching and triggering; and

FIG. 3 is a schematic wiring diagram of the electronic portions of the rhythm accompaniment device.

Referring now in greater particularly to the drawings, and first to FIG. 1, there will be seen therein an electronic organ constructed in accordance with the principles of this invention, and including a housing or case 12 with an upstanding music rack 14 and with upper and lower keyboards or manuals 16 and 18 respectively. A plurality of controls or stop tablets 20 is disposed to the left of the manuals. The organ further is provided with the usual diagram illustrating the principedals 22 for control of the pedal tones, and with a volume control or swell pedal 24. One or more loudspeakers are disposed behind a grill 26 in the front of the housing. Provision may be made for the connection of external speakers or speaker systems, all in accordance with conventional practice.

Attention next should be directed to FIG. 2. As will be seen in this figure, the organ is provided with a plurality of tone generators identified generally at 28. These tone generators may be of any suitable type, such as vibratory reed generators, or vacuum tube or transistor oscillators. The tone generators are under the control of a plurality of key switches indicated generally at 30, and respectively under the control of the keys of the manuals 16 and 18.

The generators preferably are tube type generators having normally operative plates for non-percussible tone oscillations and having normally inoperative plates for percussible tone oscillations. When one of the readout pates is energized by voltage from the key switches, the oscillations corresponding to the ultimate percussible musical tones pass through filtens and stops 32 under the control of the stop tablets 20, and from thence on to an amplifier 34 and a loudspeaker or loudspeaker system 36. The nonpercussible tones are switched differently, but also pass from the tone generators to the filters and stops etc.

A connection is made at 38, indicated as K3 to the junction of bus 31 and resistor 35 through capacitor 37 as will hereinafter be more fully described in connection with FIG. 2A. This is used to key one of the rhythm generators hereinafter to be described. The rhythm generators are indicated generally at 40 in FIG. 2, and are connected to the amplifier 34.

The tone generators are connected through a respective plurality of isolating resistors 42 to pedal switches 44 under the control of the pedals 22. The opposite sides of the pedal switches are connected to a common bus or collector 46 leading to a pedal amplifier 48. Thi amplifier in turn is connected to a first divider 50 and to a second divider 52, and this is connected to the filters and stops 32. As will be appreciated, the dividers 50 and 52 divide the frequency of the oscillations provided by the tone generators so as to produce tones, for example, respectively one and two octaves below the tones produced by the tone generators. The connections are such'that appropriate stops can be operated to supply the oscillations from either or from none of the dividers 50, 52 to the amplifier 34.

In addition to the foregoing, the pedal switches 44, or the pedals directly, bearing in mind that the showing of FIG. 2 is of schematic nature, operate a common member 54, such as a bail. As will be understood, this common member 54 is normally in a given position of rest and is displaced from this position whenever anyone of the pedals 22 or pedal switches 44 is operated. As shown in the drawings, the common member 54 is normally raised, as under the influence of a spring 56, and is depressed vertically upon ope-ration of any foot pedal. A first switch member 58 is pivotable about a fixed pivot 60 by the member 54, and is connected to cymbal keying point 62, otherwse identified at K2. The switch member 58 normally is spaced from a grounded contact 64, and is moved into engagement with the grounded contact upon downward movement of the common member 54, whereby to apply ground potential to the cymbal keying point 62 or K2.

In addition, a second pivoted switch member 66, pivoted at 68, is connected to the common member 54, and further is connected electrically to a switch point 70, otherwise identified at K1. As will be understood, the switch members 58 and 66 are insulated from one another, either through construction of the common member 54 of an insulating member, or through insulated 3 connections 32. The switch member 66 normally is spaced from a switch contact 7-2 connected to a source of positive potential, for example, 300 volts. Downward movement of the comm-on member 54 carries the switch member 66 into engagement with the fixed contacts 72.

Reference to FIG. 2A reveals one of the tone generators 28, as previously indicated to include a normally operating plate, namely the left plate, with a common cathode and grid, cooperating with other circuit elements (not shown) to produce oscillations used directly for nonpercussible tones. The right plate is normally not energized, and hence has no oscillations thereon. This plate is connected to a junction 29, and the junction is connected through a coupling capacitor 27 to the filters 32 for transmission of a tone oscillation thereto when the right plate is energized.

Potential is provided to the bus 31 through resistor 35, and as previously indicated, connection is made through the capacitor 37 to the keypoint K3 or 38. The bus 31 comprises a common bus engagea'ble by the respective movable keyswitch contacts or whiskers 41. Each of the whiskers is connected through a keyswitch isolating resistor 39 to a grounded capacitor 33 and from thence through a resistor 43 to the junction 29.

When any whisker 41 is closed against the bus 31 by its associated key, the corresponding capacitor 39 is charged through common resistor 35 and isolating resistor 39 to develop a short pulse or spike across the resistor 35 which is coupled through the capacitor 37 to the keypoint 38 or K3. Simultaneously, the right plate is biassed into operation for percussive readout. Whether percussive tones will be produced depends on the setting of the filters and stops 32.

Attention now should be directed to FIG. 3, the schematic wiring diagram of the rhythm generators. As shown in FIG. 3, the rhythm generators include, starting at the upper left hand corner of the figure, a noise generator designated generally by the numeral 74. The noise generator comprises a triode tube 76, for example a 604. The plate 78 of the tube is connected through a resistor 80 to a 3+ bus 82. This is connected through a resistor 84 to a B+ supply line 86, for example maintained at 310 volts. A decoupling capacitor or smoothing capacitor 88 is provided on the plate side of the resistor 84. The plate also is connected by a capacitor 90 to a junction 92 leading to a noise generator output line 94. The junction also is connected through a capacitor 96 to the ground.

The grid 98 is connected to a grounded resistor 100, and to a capacitor 102. This capacitor is connected in turn to a grounded capacitor 104 and a grounded coil or inductance 106, and further to a grounded resistor 108, the last-mentioned capacitor, the inductors, and the resistor thereby all being in parallel. The cathode 110 is connected to a tap 112 on the inductance 106, relatively near the grounded end thereof.

The noise generator is in the nature of a super-regenerative detect-or which inherently produces a broad band or noise spectrum.

'By way of example, the circuit elements heretofore noted may be as follows:

Resistor 80 ohms 100,000 Resistor 84 do 68,000 Resist-or 100 do 470,000 Resistor 108 do 15,000 Capacitor 88 Microfarads .20 Capacitor 90 do .001 Capacitor 96 micro-microfarads 380 Capacitor 102 do 56 Inductance 106 -millihenries 24 The noise generator 74 serves as the signal source for both the brush and the cymbal tones. In connection therewith, there is provided a brush keyer 114, including one-half of a triode tube, such as a 6EU7. The plate 116 of this tube is provided with potential through a resistor "thereby to 4 118 from the 13+ bus 82. The plate further is connected through a capacitor 120 and a resistor 122 to wires 124 and 126 leading to a junction 128. This junction is connected through a capacitor 130 and a resistor 132 to a junction 134 and an output line or wire 136, the latter being connected to the amplifier 34.

The cathode 1 38 of the brush keyer section of the triode tube, the tube hereinafter being identified by the numeral 140, is grounded through a resistor 142. The grid is connected to a junction 144, and this junction is connected through a resistor 146 to a junction 148. The junction 148 is connected through a resist-or 150 to a negative supply line, for example 22 volts.

The output line 94 of the noise generator is provided with a junction 152, and this junction is connected through a resistor 154 and a capacitor 156 to the junction 144, supply a noise signal to the grid 158. The brush keyer comprises an amplifier which is normally cut off by the 22 volts potential applied through the resistor 1'50. Means is provided for overcoming this negative potential to render the brush keyer conductive, as hereinafter set forth.

In particular, there is provided a one .shot key generator 160. This one shot key generator comprises a twin triode tube, such as a 6EU7. One plate thereof is identified by the numeral 162, and is connected to a junction 164 which leads through a capacitor 166 and a resistor 168 to the junction 148. This junction is shunted to ground by a capacitor 170. The junction 164 also is connected through a plate load resistor 172 to the B+ line .82.

The corresponding cathode 174 is connected to a junction 176 which is grounded through a resistor 178. The corresponding grid 180 is connected to a junction 182. This junction is returned through a resistor 184 to the cathode junction 176, and it also is connected through a coupling or feedback capacitor 186 to a junction 188 connected to the other plate 190 of the twin triode tube hereinafter identified by the numeral 192. Finally, the junction 182 is connected through a .switch 194 to keying point K3, also identified by the numeral 38. The switch 194 normally is open, and is closed by a designated one of the stop tablets 20, when so desired.

The second plate 190 is connected to the junction 188 and a plate load resistor 196 to the B+ line 82. The second grid 198 is grounded, while the second cathode 200 is connected to the junction 176, and hence in parallel with the first cathode 174. e

The one shot key generator 160 will be recognized as a circuit in the nature of a monostable multivibrator or flip-flop circuit. One-half of the tube normally is conducting and the other is not. This condition is momentarily reversed when a key switch is closed to apply a positive voltage spike to the keying point K3, whereupon a positive potential is transmitted to the junction 148 to overcome the normal negative biasing, and thereby to render the brush keyer 114 momentarily operative.

The specific circuit values of the components just discussed are susceptible to variation. However, by way of example, the last values are set hereinafter as follows:

Resistor 118 ohms 100,000 Resistor 122 do 47,000 Resistor 132 do 68,000 Resistor 142 do 1,500 Resistor 146 megohms 1 Resistor 150 d0 2.2 Resistor 154 ohms 100,000 Resistor 168 do 100,000 Resistor 172 do 100,000 Resistor 178 do 4,700 Resistor 184 do 470,000 Capacitor 120 micro-microfarads 470 Capacitor 130 do 220 Capacitor 156 do 390 A cymbal tone is also taken from the noise generator, and this is controlled by a cymbal keyer 202, comprising a pcntode tube 204, the plate 206 of which is connected to a junction 208, and thence through a resistor 210 to the B+ line 82. The tube 204 may, for example, be a type 6BA6.

The cathode 212 of this tube is connected to a junction 214, and hence through a resistor 216 to ground. A control grid 218 is connected to a junction 220, and this is connected through a resistor 222 to a junction 224. This latter junction is shunted to ground by a capacitor 226, and is also connected to a resistor 228 leading to a normally open switch 230 controlled by one of the stop tablets 20, and from there to the keying point K2, also identified by the numeral 62.

The junction 220 is connected direct to a junction 232, and this is connected through a resistor 234 to a junction 236, the latter being connected through a resistor 238 to the junction 224. The junction 236 is connected to a negative bias line, for example --22 volts.

The second or screen grid 240 of the tube is connected to a junction 242 which leads through a potentiometer 244 to ground. The potentiometer is provided with a grounded sliding tap 246. The junction 242 also is connected through a biasing resistor 248 to the B+ line 82.

The output junction 152 from the noise generator is connected through a series resistor 250 and capacitor 252 to the junction 232, whereby to supply a noise signal to the control grid 218. As will be apparent, the suppressor grid 254 is connected direct to the junction 214 on the cathode 212.

The cymbal keyer is in the nature of an amplifier which is normally cut off by the -22 volts bias. When the keying point K2 or 62 is grounded, the biasing is changed to render the cymbal keyer 202 conductive, whereby the noise signal is amplified by the tube 204. A capacitor 256 connects the cymbal keyer output junction 208 to the junction 128.

As again will be understood, the values of the circuit elements are susceptible to variation. However, by way of example, the following are set forth:

Resistor 210 ohms 68,000 [Resistor 216 do 470,000 Resistor 222 megohms 1 Resistor 234 do 3.3 Resistor 238 do 4.7 Resistor 250 ohms 100,000 Resistor 246 do 50,000 Resistor 248 do 100,000 Capacitor 226 microfarads .15 Capacitor 252 micro-microfarads 560 Capacitor 256 microfarads .001

The junction 128 is shunted to ground by a tuned circuit 258, comprising a variable inductance 260 and a parallel capacitor 262. This tuned circuit determines the band or range of noise frequencies that will be passed to the audio frequency output.

In connection therewith, there is a shimmer generator 264 comprising the second-half of the triode tube 140. The plate 266 thereof is connected through a resistor 268 to the B+ line 82. The plate also is connected to a junction 270, and this leads through a capacitor 272 to the junction 274 between the wires 124 and 126, and hence to the junction 128.

The cathode 276 of the second-half of the tube 140 is connected through a resistor 278 and a parallel capacitor 280 to ground.

The control grid 282 is connected to a grounded resistor 284, and to a capacitor 286. This capacitor in turn is connected to a grounded resistor 288 and to a capacitor 290. The capacitor 290 is connected to a junction 292 between a grounded resistor 294 and a capacitor 296 leading to the junction 270.

Values, which again are to be considered only, are set forth as follows:

as exemplary Inductance 260 millihenries. Capacitance 262 .0018 microfarads. Capacitance 280 25 microfarads, 6 volts. Capacitance 286 .0068 microfarads. Capacitance 290 .0068 microfarads. Capacitance 296 .0068 microfarads. Resistor 268 100,000 ohms. Resistor 278 2700 ohms. Resistor 284 1 megohm. Resistor 288 560,000 ohms. Resistor 294 330,000 ohms.

The parallel resonant or tank circuit 258 comprises a formant filter tuned to be resonant at higher audio frequencies, for example on the order of 8 kilocycles, or possibly higher. This formant filter determines the tonality of cymbal and to some extent the brush, while the shimmer generator 264, which is an oscillator operating in the high sub-audio frequency range, for example 17 cycles per second, modulates the cymbal or brush tones.

In addition, there is shown a bass drum generator 298. The bass drum generator is an oscillator which is normally biased off, and which includes a triode section of a tube 300, which may be a 6EU7 tube. The left half of the tube as shown in FIG. 3 is illustrated as being nonconnected, since it is incorporated in other of the electronic circuits of the organ, not pertinent at the moment. The cathode 302 is grounded through a resistor 304 having a grounded, sliding tap 306 thereon for controlling the bias on the tube.

The plate 308 is connected to a junction 310, and this leads through a plate load resistor 312 to the B+ bus line 82. The plate also has an output circuit comprising a connection from the junction 310 through a resistor 314 to a junction 316. The junction is shunted to ground through a capacitor 318. It also is connected through a blocking or isolating capacitor 320 and a series resistor 322 to the junction 134 leading to the output 136.

The grid 324 is shunted to ground by a resistor 325 and is connected through a capacitor 326 to a junction 328. This junction is shunted to ground through a resistor 330. It also is connected to a capacitor 332 leading to junction 334. A feedback capacitor 336 is connected from the plate 308 to the junction 334. In addition, the junction 334 is connected through a resistor 338 to a junction 340, this junction being grounded through a resistor 342, and also connected through a capacitor 344 to a keying junction 346, the latter being shunted to ground by a resistor 348. The junction 346 is connected by means of a series resistor 350 to a switch 352 leading to keying point K1 or 70. The switch 352 is normally open, and is closed by selective manipulation of an appropriate one of the stop tablets 20.

The bass drum generator 298 normally is biased oil". When the switch 252 has been closed, each time one of the pedals 22 is operated, positive potential is applied through the switch 66, 72 to the keying point Kl or 70, and a positive pulse is transmitted to the generator 298. The capacitor 344 insures that this will be a pulse, and not a continuous voltage. A damped wave oscillation is introduced for a predetermined interval corresponding to that of a typical drum. The oscillator operates in the vicinity of 50-70 cycles per second.

Suitable circuit values again could no doubt be assigned by any competent person skilled in the art, but

certain values are listed hereinafter as exemplary:

Resistor 304 ohms 5,000 Resistor 312 do 270,000 Resistor 314 d0 680,000 Resistor 322 do 100,000

7 Resistor 338 do 470,000 Resistor 325 do 680,000 Resistor 342 do 100,000 Resistor 348 do 220,000 Resistor 350 do 680,000 Capacitor 320 microfarads .068 Capacitor 318 do .01 Capacitor 326 do .0016 Capacitor 332 -do .0033 Capacitor .336 .do .0016 Capacitor 344 do .068

As will now be apparent, the organist can play the electronic organ in the normal manner. The three rythm accompaniments, namely bass drum, brush, and cymbal can be brought in one at a time or in any desired combination by use of the appropriate stop tablets, and the rhythm accompaniments are timed perfectly with the players rhythm. It is not necessary for the organist to make any effort to adapt his playing to the tempo of the rhythm pattern, since the rhythm pattern is keyed by the organists melody playing.

The bass drum and cymbal tones accompany playing of the pedals, as is desirable. On the other hand, the brush tone accompanies playing of the manuals, as also is desirable.

Various changes in structure will no doubt occur to those skilled in the art, and will be understood as forming a part of the present invention insofar as they fall within the spirit and scope of the accompanying claims.

The invention is claimed as follows:

1. An electronic musical instrument comprising a plurality of tone generators for producing electronic oscillations corresponding to musical tones, a plurality of keys and a plurality of pedals, a plurality of switches repeetively selectively operable by said keys and said pedals, amplifier means, said switches respectively selectively interconnecting said tone generators and said amplifier means upon selective operation of said keys and said pedals selectively to transmit oscillations from said generators to said amplifier means, electro-acoustic transducing means connected to said smplifier means for converting the amplified electric oscillations into sound, a plurality of percussive type tone generators respectively generating oscillations corresponding to different percussive efiects, means operable substantially instantaneously as an incident to depression of a key to transmit a tone oscillation from at least one of said percussive tone generators to said amplifier means, and means operable substantially instantaneously as an incident to depression of a pedal to transmit at least one tone oscillation from at least one other of said percussive tone generators to said amplifier means, said percussive generator tone oscillations respectively being transmitted simultaneously with electronic oscillations from said musical tone generators.

2. An electronic musical instrument as set forth in claim 1 wherein at least one of the percussive type tone generators includes a noise generator.

3. An electronic musical instrument as set forth in claim 2 wherein at least one additional percussive type tone generator comprises a damped oscillator normally biased off.

4. An electronic musical instrument comprising a plurality of tone generators for producing electric oscillations corresponding to musical tones, amplifier means, a plurality of keys and a plurality of pedals, a plurality of switches respectively selectively operable by said keys and pedals and selectively interconnecting said tone generators and said amplifier means upon operation of said keys and said pedals selectively to transmit oscillations from said generators to said amplifier means, electro-acoustic transducing means connected to said amplifier means for converting the amplified electric oscillations into sound, a plurality of percussive type tone generators respectively generating oscillations corresponding to different percussive effects and including a noise generator and a damped oscillator, means operable substantially instantaneously as an incident to depression of a key to transmit a tone oscillation from the noise generator to said amplifier means, and mean operable substantially instantaneously as an incident to depression of a pedal to transmit tone oscillations from either of said noise generator and said damped ocillator to said amplifier means, said percussive generator tone oscillations respectively being transmitted simultaneously with electronic oscillations from said musical tone generators.

5. An electronic musical instrument comprising a plurality of tone generators for producing electric oscillations corresponding to musical tones, amplifier means, a plurality of keys and a plurality of pedals, a plurality of switches respectively selectively operable by said keys and said pedals and selectively interconnecting said tone generators and said amplifier means selectively to transmit oscillations from said tone generators to said amplifier means, electro-acoustic transducing means connected to said amplifier means for converting the amplified electric oscillations into sound, a plurality of percussive type tone generators respectively generating oscillations corresponding to different percussive effects, a common member movable upon depression of any pedal, and switch means connected to said common member and operated thereby to transmit at least one percussive oscillation from at least one of said percussive type tone generators to said amplifier means, said percussive generator tone oscillations respectively being transmitted simultaneously with electronic oscillations from said musical tone generators.

6. An electronic musical instrument as set forth in claim 5 and further including an additional switch operable by said common member, said additional switch being operatively connected to said amplifier means and to at least one of said percussive type tone generators being operable to transmit a percussive tone oscillation from at least one other of said percussive type tone generators to said amplifier means.

7. An electronic musical instrument as set forth in claim 6 wherein an additional one of said percussive type tone generators is of a type actuated by a voltage spike, and means interconnecting said key switches and said additional percussive type tone generators to transmit a voltage spike thereto upon operation of any of said keys.

8. An electronic musical instrument comprising a plurality of tone generators for producing electric oscillations corresponding to musical tones, amplifier means, a plurality of keys and a plurality of pedals, a plurality of switches respectively selectively operable by said keys and said pedals selectively interconnecting said tone generators and said amplifying means selectively to transmit oscillations from said generators to said amplifying means, electro-acoustic transducing means connected to said amplifying means for converting the amplified electric oscillations into sound, a plurality of percussive type tone generators respectively generating oscillations corresponding to different percussive effects, gate means operatively connecting at least one of said percussive type tone generators to said amplifier, said gate means normally being off and being turned on upon application of a voltage spike to said gate means, and means operatively interconnecting said key switches and said gate means to apply a voltage spike thereto upon closure of any of said key switches, said percussive generator tone oscillations respectively being transmitted simultaneously with electronic oscillations from said musical tone generators.

9. An electronic musical instrument comprising a plurality of tone generators for producing electronic oscillations corresponding to musical tones, a plurality of keys and a plurality of pedals, a plurality of switches respectively selectively operable by said keys and said pedals, amplifier means, said switches respectively selectively interconnecting said tone generators and said amplifier means upon selective operation of said keys and said pedals selectively to transmit oscillations from said generators to said amplifier means, electro-acoustic transducing means connected to said amplifier means for converting the amplified electric oscillations into sound, percussive type tone generating means generating oscillations corresponding to percussive effects, and additional switch means operatively connected to at least some of saidkeys and said pedals and operatively interconnecting said percussive type tone generating means to said amplifier means upon operation of said additional switch means, said percussive generator tone oscillations being respectively transmitted simultaneously with electronic oscillations from said musical tone generators.

References Cited by the Examiner UNITED STATES PATENTS Bergman 84-1 .03 X Riggs et al. 84-126 Campbell 84-1.03 Mabuchi 84-1.01 X Gibbs et al. 841.26 George 84-1.03

ARTHUR GAUSS, Primary Examiner.

I. C. EDELL, J. S. HEYMAN, Assistant Examiners. 

1. AN ELECTRONIC MUSICAL INSTRUMENT COMPRISING A PLURALITY OF TONE GENERATORS FOR PRODUCING ELECTRONIC OSCILLATIONS CORRESPONDING TO MUSICAL TONES, A PLURALITY OF KEYS AND A PLURALITY OF PEDALS, A PLURALITY OF SWITCHES RESPECTIVELY SELECTIVELY OPERABLE BY SAID KEYS AND SAID PEDALS, AMPLIFIER MEANS, SAID SWITCHES RESPECTIVELY SELECTIVELY INTERCONNECTING SAID TONE GENERATORS AND SAID AMPLIFIER MEANS UPON SELECTIVE OPERATION OF SAID KEYS AND SAID PEDALS SELECTIVELY TO TRANSMIT OSCILLATIONS FROM SAID GENERATORS TO SAID AMPLIFIER MEANS, ELECTRO-ACOUSTIC TRANSDUCING MEANS CONNECTED TO SAID AMPLIFIER MEANS FOR CONVERTING THE AMPLIFIED ELECTRIC OSCILLATIONS INTO SOUND, A PLURALITY OF PERCUSSIVE TYPE TONE GENERATORS RESPECTIVELY GENERATING OSCILLATIONS CORRESPONDING TO DIFFERENT PERCUSSIVE EFFECTS, MEANS OPERABLE SUBSTANTIALLY INSTANTANEOUSLY AS AN INCIDENT TO DEPRESSION OF A KEY TO TRANSMIT A TONE OSCILLATION FROM AT LEAST ONE OF SAID PERCUSSIVE TONE GENERATORS TO SAID AMPLIFIER MEANS, AND MEANS OPERABLE SUBSTANTIALLY INSTANTANEOUSLY AS AN INCIDENT TO DEPRESSION OF A PEDAL TO TRANSMIT AT LEAST ONE TONE OSCILLATION FROM AT LEAST ONE OTHER OF SAID PERCUSSIVE TONE GENERATORS TO SAID AMPLIFIER MEANS, SAID PERCUSSIVE GENERATOR TONE OSCILLATIONS RESPECTIVELY BEING TRANSMITTED SIMULTANEOUSLY WITH ELECTRONIC OSCILLATIONS FROM SAID MUSICAL TONE GENERATORS. 